Method of making tripping coils



Dec. 14 1926. 1,610,230

I w. M. AUSTIN METHOD OF MAKING TRIPPING COILS Filed Sept. 27, 1922 2 Sheets-Sheet 1 INVENTOR Dec. 14,1926. 1,610,230

W. M. AUSTlN METHOD'OF MAKING TRIPPING COILS Filed Sept. 27, 1922 2 Sheets-Sheet 2 INVENTOR ATTORNEY UisfiTfE is an a .watrnn swissviirs "rsnnsrnvsnm assessors"ir o-.-wnsrinenoiisn En'EorR'Ic AN'DMANUFAGTUBING COMPANY, A CQRPORATEON or rnnissytvenrs.

f m mos or iuairmefrnrrrrive come. 1

.Th e.ii i 1i elate c c t es er and more particularly. to tripping co ls thereei diale the l@fieek es-thesame. Theob ect, of invent on is to prov de.

a metallic @011 which maybe n egrals cast by .agsingle operation.

- M the s e a. T Isle.s ierlegseeek b is su e e f the. casting 'thereof.

.-A.;i. r, materi lly;redeeet iesieee eletesre:

'tofore requ rec l sc -ls ietallie' structed by v ier ei zed embe eerel tiens 3 W? ime;as-@e @1.;t see b texfeeldtWe ess' but more frequently a heat treatment,, in

ieiei sies atlees e ir result, Such processes are complicatedand expensive.

By my invention, I providea co l so designed that it maybe cast by'a' single operation, requiringbut a simple mold pattern.

Figure 1 illustratesa conventional carbonand-air circuit breaker equipped with a tripping coil embodying my invention.

7 Figure 2 isan edge viewoi the coil as it appears upon removing from the mold. I Figure 3 is a sectional view of the same,

taken along the, line III-III of Figure. 2.

'.ber of convolutions 4 and'endj members 5 and 6 extending parallel to the majorflaxis of the coil 1. The convolutions 6 are substantially alike incross-sectional area, each has dilierentcross-sectional areas in different portions thereof, as indicated in Figure 4:. I

i may be seen-that the radial thickness of each convolution 4 is less at its outer side than A ipl ication firea'sseataw,192 serialnq-fiflafiimil l i et o m n ei tieeie r1 1 met llic cs ao smkshwe. thet I n where io h I; ,Qbjfect. oii to in h me fec re f fi -f Ian-i ii \sw: w .1. w le hav eseeteiii abseei eez bending strips of metal thrpugh' addition to the mechanical operation was the completed mold and a cylindrical dry I V V of the radii of curvatur By a comparison of Figures 2I'and 4t, 1t V I several adgacent convolutions .L-ior the purf .0... 4L0. 11:... .h Qe ted; ee thickness .of each convolut on is greater at the outer side than. at its inner side.

Because o lfftliis.disposition or it. ier s blsrte ee -iiiethe ff ct 1 Ian-a d? tional turn at the innerdsidepttheceil with;

sei e ythl flev i tre l l meee e e;esi tse lrtsh npFieure-fi. .eeerelseee at t1 e;- .I e .e e occupy the endwise space or" three convoluside; H f

out .incr

ti outer and. p)

e iate iie'rtiees .e eehmrtl Eat convolution is ipro short st .1 e ess$..8 -.e p e tew.- t9 h =i i eses.8tqtt ese;

ons. By reason or the pecu- V liar design of the shoulder 7 and recess 8; it

is possible to mold the coil 3 in a single operation and with a single cylindrical core member. I

The disposition of the shoulders 7 and recesses 8 is such that there is nothing to interfere with drawing the pattern from the sand. 'By'a' comparisonflof Figs. 2 andi3 it may be observed thatthere is practically a. uniform distance'between corresponding points on the several convolutions throughout their length.

it makes possible the use of a'green-sand casting of the coil.

thereof.

that they occupy therelative positions shown in F guresfi and 6. The coils are then machined and ClllllGC-l for openings 9,'1 l.and

.12; These-openings are for attaching screws and blnding posts, one of which is shown, as

'lhisfeature is of great importance from a practical standpoint, as 1 sand core in the at18,inFigure 6. Thepressing process also,

serves to flatten out'the abrupt curves in each COHVOlLltlOl'l and thGlQbY IHCPGZISQS the length Suitable air spaces 14 are'left between the iio mold and the simplest core. The cross-sec- $101191 shapes of the convolution 4 are varied at points throughout their length in order that all available space may be used to the best advantage.

My invention is not limited to the forms that areillustrated or to the arrangement thereof, since modifications may be made therein within the spirit and scope of the invention, as set'torth in the appended claims.

.I claim as my invention:

' l. A method of making a helical element which consists in casting the helix with spaces between the various convolutions and then subjecting the helix to pressure, where by the 'convolutions are brought nearer together. v 1 2. The method of making a helical member which consists in casting a true helix and then submitting the helix to mechanical pressure.

3 The method of making a helical member which consists in casting an extended helix and then submittingthe helix to me chanical pressure applied in the direction of the axis of the helix.

4. The method of making a helical element which consists in casting a helix, with the convolutions in an extended position, and then subjecting the helix-to pressure in the direction of its axis, whereby the conv0lutions are brought close together.

5. The method of making a helical element which consists in casting a helix with the various vconvolutions in such extended relation that. sand may be used as a molding element between said convolutions, then removing said helix from the mold and subjecting the same to pressure, whereby the varlous convolutions are brought nearer together.

6. The method of making a helical element,

which consists in casting the same in a greensand mold.

7. The method of making a helical element which consists in casting said element, with the various convolutions spaced apart, and with portions of said convolutions hav ng plane surfaces with abruptly curved surfaces between said plane surfaces, then compres- WALTER M. AUSTIN.

surfaces are materially in- 

